Temporomandibular Joints (TMJs)

A CBCT scan will not demonstrate the position or integrity of the disk, as the disk is not a calcified structure. A CBCT scan that visualizes the TMJs may be evaluated for osseous changes to the mandibular condyle or glenoid fossa of the temporal bone (Figure 16). These osseous changes may result from trauma/fracture, degenerative changes or neoplastic processes.^23,24 If demonstration of the soft tissue components of the joint is requested by the clinician, another type of imaging such as magnetic resonance (MR) is recommended. The musculature of the TM joints cannot be assessed by CBCT; the use of a CBCT scan for diagnosis and treatment of myofascial pain disorder or disk displacement is not indicated and thus will not be useful to the clinician.

If osseous evaluation of the TM joints is requested, it is important to choose a scan height to adequately image the entire joint space.²³ A drawback of the units using an image intensifier as the detector is that the TM joint spaces are often incompletely imaged or will be visualized at the edge of the spherical scan and prone to distortion.

Figure 16. Osteophyte formation on both condyles with sclerotic changes in glenoid fossae.

Figure 16. Osteophyte formation on both condyles with sclerotic changes in glenoid fossae.